Circuit Description
This diagnostic monitors the signal from the camshaft position (CMP) sensor. The CMP sensor is a magnetic generator type sensor, producing an alternating current signal. The CMP sensor sends this signal to the powertrain control module (PCM) to indicate the camshaft position. The CMP signal is used by the PCM to modify fuel injection pulse, ignition timing and misfire detection.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0340 Camshaft Position (CMP) Sensor Circuit
Conditions for Running the DTC
| • | DTC P0335, P0336, P0385, or P0386 are not set. |
| • | The engine is running. |
| • | DTC P0340 runs continuously once the above conditions are met |
Conditions for Setting the DTC
No camshaft position sensor signal to the PCM for 16 crankshaft revolutions.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the MIL after 3 consecutive trips without a fault. |
| • | The PCM clears a History DTC after 40 consecutive warm-up cycles without a fault. |
| • | Use the scan tool Clear DTC Information function. |
Diagnostic Aids
Check for any of the following conditions:
| • | A loose CMP sensor or damage, foreign material on the signal marks of the camshaft gear can cause a DTC P0340. |
| • | An intermittent malfunction may be caused by a fault in the CMP sensor electrical circuit. Inspect the wiring harness and the components for an intermittent condition. Refer to Intermittent Conditions . |
Repair any electrical circuit faults that were found. Refer to Wiring Repairs .
The information included in the Freeze Frame data can be useful in determining the vehicle operating conditions when the DTC first set.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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The Diagnostic System Check - Vehicle prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
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This step determines whether the DTC P0340 is the result of a hard failure or an intermittent condition.
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This step tests the CMP sensor input circuit.
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After replacing the PCM a new minimum throttle position and idle speed must also be established.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||
Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | ||
Did the DTC fail this ignition? | -- | Go to Step 3 | Go to Diagnostic Aids | |
3 |
Did the test lamp illuminate? | -- | Go to Step 4 | Go to Step 7 |
4 |
Is the voltage near the specified value? | 12 V | Go to Step 5 | Go to Step 8 |
Is the voltage near the specified value? | 5.0 V | Go to Step 10 | Go to Step 6 | |
6 |
Did you find and repair a condition? | -- | Go to Step 13 | Go to Step 9 |
7 |
Did you complete the repair? | -- | Go to Step 13 | -- |
8 |
Did you complete the repair? | -- | Go to Step 13 | -- |
9 |
Did you find and correct a condition? | -- | Go to Step 13 | Go to Step 12 |
10 |
Did you find and correct a condition? | -- | Go to Step 13 | Go to Step 11 |
11 | Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
Did you complete the replacement? | -- | Go to Step 13 | -- | |
13 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 14 |
14 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |
